OK i have been told by a certain very experienced person on the forum (the admin) about matching and flowing the case when a 70 Kit is fitted!, i understand matching is were the rest of the case is adjusted/modified in order to compensate for the 70cc Cylinder, and i also understand flowing is were the case is grinded away so the hole were the mixture goes through is made bigger! So can any1 go into abit more detail on these two processes as i understand they are usually bypassed when a 70 kit is fitted!, so can any1 go into abit more detail on these two subjects and maybe post some pictures to make it even more clearer? Thanks alot any help is always appriciated!
thought i might be first to reply to this one. ill take some pics of the befor pics of a 50 engine case half with the 70 kit gasget on so you can see what needs taking out. basicly what this physically does is create less turbulance inside the engine. if there are any steps inside an engine the air changes direction (some times it makes a right angle of pressure) usually the change in direction of air when fitting a 70 to a stock engine is towards the barrel itself, physically blocking the port with the mixture its trying to feed. because the turbulant air is moving acros the port rather than into it, the port only gains mixture when there is vacume, where as in a correctly matched engine where the gas is flowing as it should there is positive pressure that is disapated by shooting the mixture into the cylinder befor it even has chance to create a vacum. its like running upstairs. but ye, ill let you fester on that for a while and ill sort some pics out
the way i have always thought of matching or flowing of the crankcase is that its almost like inertia, the air is forced a certain way by the crankcase and it wants to keep going in a straight line, so in order to make it work better that straight line has to be exactly where you want it, its not going to do it itself its a lot like a computer, it wont do anything you dont tell it to do
exactly right, but that line doesent have to be straight. aslong as its as straight as it can be with any curves soft and uniform the air will stick to it (put a candle behind a milkbottle and blow, now try a dvd case)
Oright yea i get the basic idea now, so the air needs as much curves and things that will make it flow well as possible or it will go of course/lose its direction? And when matching and flowing is done it creates a good course for the air?
yes, but also the groves need to direct air into the right place without it falling down. think of a curved drainpipe. at steep turns water will rush out of the side even tho its half full of water when flat. the trick is getting the most flow while removing the least material as primary compression plays a big role untill your up to top revs. at this point its prittymuch all pipe as the cycle is so fast
